Grow Mediums

Posted by
Sinem
on October 29, 2018

The practice of hydroponics allows crops to be grown without
the use of soil, but that doesn’t mean that the plants are to be suspended in
mid-air! Alternative substances must be
used to provide root support, water supply, and other functions which would
usually be imparted by soil, while dispensing with the inconveniences. These substances are known as grow
mediums. Let’s consider a few
of the hydroponic grow mediums available, with their advantages and uses.

Rockwool and Perlite

These two have been described as the industry standards of hydroponic
grow mediums. Mineral wools are created
by melting rock until if reaches a treacle-like consistency, then drawing out
fibres which quickly cool, resulting in a fleece-like fibrous substance. Besides its use in the hydroponics industry,
mineral wool has been used as a thermal and acoustic insulator, and also in
industrial filters.

Many professional hydroponics companies prefer a rockwool growing
medium as its consistency allows for an optimum oxygen/water balance. The texture of this growing medium provides
what many see as an ideal balance between three critical properties of any
hydroponic substrate: breathability (to allow air in), permeability (for
retention of fluid) and a consistency which allows the roots of the plants to anchor
themselves firmly and grow freely.

Perlite
is a mineral wool created from volcanic rock, and is lighter and less dense
than most rockwool. It is good for use
with wicking hydroponics systems, where water and nutrients are drawn up
through the substrate by capillary action.
Experienced enthusiasts and professionals may use perlite as a hydro
grow medium, that is, for minimalist systems which use very little substrate
and where all variables are directly controlled by the operator. This kind of setup can yield exceptional results
with careful monitoring and regulation. Less
experienced hobbyists may prefer a denser growing medium, which takes a lot of
the hard work out of the process. Another
consideration is that perlite dust is harmful, so it must be handled very
carefully.

Expanded Clay Pebbles

Clay pebbles are
one of our most popular supplementary media due to the unequalled root support
they provide. Heating fragments of clay
to over one thousand degrees converts it into a light weight, highly porous medium
which allows both air and water to pass through and boasts excellent drainage
properties. They are totally inert, are
easily colonized by beneficial bacteria, and can be washed and reused after
each crop.

‘Grow medium coco’ or ‘hydro coco’ are names given to
coconut fibre which is used as a grow medium, or as part of mixed grow mediums
UK experts recommend for organic hydroponics systems. Once again, water and oxygen capacities are
critical and coconut fibre scores excellently in both these areas. Aside from its completely organic nature,
ecologically conscious growers may prefer it to rockwool as the latter never
fully breaks down after disposal.
Coconut fibre, of course is fully compostable. Additionally, high quality hydro coco
contains only minimal levels of native nutrients, and is therefore suitable as
a grow medium with mixed nutrients solutions in mind.

Guanokalong

Not a growing medium, but an all natural additive which can increase
the size and number of flowers and fruit, and enhance the taste of your
produce. Animal waste -based fertilizers
have been common agricultural practice for centuries, so this product, famously
made from bat droppings, has a strong heritage at which we should not turn up
our noses.